ath10k: allow dynamic bandwidth in hw rate control

Frames were never retransmitted with
different/lower bandwidths, e.g. only 80MHz
bandwidth was used when dealing with a VHT80
peer.

Allow HW rate control to try out different
bandwidths when retransmitting. This increases
robustness.

Also, document the parameter properly.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/mac.c

@@ -1964,7 +1964,7 @@ static int ath10k_start(struct ieee80211_hw *hw)
 		ath10k_warn("could not enable WMI_PDEV_PARAM_PMF_QOS (%d)\n",
 			    ret);
 
-	ret = ath10k_wmi_pdev_set_param(ar, ar->wmi.pdev_param->dynamic_bw, 0);
+	ret = ath10k_wmi_pdev_set_param(ar, ar->wmi.pdev_param->dynamic_bw, 1);
 	if (ret)
 		ath10k_warn("could not init WMI_PDEV_PARAM_DYNAMIC_BW (%d)\n",
 			    ret);

drivers/net/wireless/ath/ath10k/wmi.h

@@ -2234,7 +2234,12 @@ enum wmi_pdev_param {
 	 * 0: no protection 1:use CTS-to-self 2: use RTS/CTS
 	 */
 	WMI_PDEV_PARAM_PROTECTION_MODE,
-	/* Dynamic bandwidth 0: disable 1: enable */
+	/*
+	 * Dynamic bandwidth - 0: disable, 1: enable
+	 *
+	 * When enabled HW rate control tries different bandwidths when
+	 * retransmitting frames.
+	 */
 	WMI_PDEV_PARAM_DYNAMIC_BW,
 	/* Non aggregrate/ 11g sw retry threshold.0-disable */
 	WMI_PDEV_PARAM_NON_AGG_SW_RETRY_TH,